Great day. Finally got to a 100 yard range today. Got the rifle sited in at 50 yards. At 100 could not tell if we were hitting the target or not so we put a couple half liter bottles on the ground. Was consistently hitting the bottle. Not every time but often enough to know it is sited properly. Everything else was on me. Granted we did most of the shooting from a table and mini tripod. Neither one of us could hold on the target well enough at 100 yards. Buddy had his Marlin Model 60. The scope he had needed zeroed at 50 yards. Then all he has to do is turn the turrets to his yardage and aim. 25, 50 and 100 yards were all dead on with his ammo he had. It was a BDC scope for .22. Now I want to get a BDC scope for the M4. It is an Olympic Arms Plinkster Plus flat top. Put the P-223(?) offset rings topped with a cheap Tasco 3-9X 40 scope. Went cheap on the scope just to get started. It is working well just not as convenient as a BDC scope. Even played with the cheap red dot. Got consistent hits at 50 yards but lost the bottle at 100. Got it about 2 out 5 at 100. Now to get back out there to get the groups tighter. Also going to work on a "target" camera and homemade auto loading reactive target system. For the camera I have an IP enable security camera. Figure a 12 volt battery, inverter, wireless router and tripod at one end and a laptop or Ipad at the other. Easier to see target if we don't take out the camera. Hopefully the camera will be able to see far enough we can it out of the way.